In the dire climate change scenarios, millions of people may die in decades to come. But here’s a major reason to implement clean energy now: According to a new report from Unicef two billion children—more than a quarter of the world’s population—are exposed to air pollution at levels the World Health Organization considers “a long-term hazard”. “Even though the toxic cocktail of chemicals in air pollution is largely invisible to the naked eye, these elements are deadly and affect children’s health and well-being,” the study’s authors write.